use std::collections::HashSet;
pub fn new_count_distinct(input_str: &str) -> usize {
    let mut set = HashSet::<String>::new();
    let iter = input_str.split(",").map(|s| s.to_owned());
    for s in iter {
        set.insert(s);
    }
    set.len()
}

#[test]
fn test_fn() {
    let num = new_count_distinct("hello, worlds");
    assert_eq!(num, 2)
}
